Switching power supply and electronic device

A switching power supply, including a transformer, wherein the transformer includes a frame, and the transformer further includes a multi-layer winding structure arranged on the frame, and different winding units of the multi-layer winding structure are distributed at intervals along a target direction;

• at least one winding unit of the multi-layer winding structure includes a first winding of a primary side of the transformer;
• at least one winding unit of the multi-layer winding structure includes a second winding of a secondary side of the transformer;
• at least one winding unit of the multi-layer winding structure includes a shielding winding;
• in the multi-layer winding structure, at least one group of shielding windings is wound in parallel in the same layer as the first winding, and/or:
• at least one group of shielding windings is distributed between the first winding and the second winding;
• wherein the shielding winding is located on the primary side of the transformer;
• at least one end of the shielding winding is connected with an oscillation reduction unit for eliminating or weakening oscillation.